We propose to carry out molecular dynamics (MD) simulations of large assemblies of biomolecules. These simulations will cover membrane-protein systems, protein-DNA complexes, muscle proteins, viral coat proteins, and quantumchemical properties of retinal in bacteriorhodosin. In addition, we propose to investigate the feasibility of interactive MD of biomolecular systems. The calculations pose a challenge because of the large systems sizes ( up to 60,000 atoms), the long-time scales ( microsecond), and the requirements for a quantuchemical evaluation of forces. The group has recently developed new molecular dynamics code for parallel machines. This code, as well as other widely used molecular dynamics programs, will be utilized to conduct the proposed simulations.